1. Field of the Invention
This invention relates to an accessory grip for use with an elongate instument, such as a writing pencil or a cosmetics pencil, and to a method for making the same.
2. The State of the Art
Since the vulcanization of rubber, various natural and synthetic polymers have been formed into aids for gripping objects. A common grip aid prevalent now is on writing pens, where the elonate pen""s plastic body is molded with, or overmolded with, a soft polymeric grip, such as described in U.S. Pat. No. 6,036,385. Another common grip aid is one which is made separately and the user then places over a pen or pencil. Such devices are described in the following U.S. Pat. Nos. 4,601,598; 4,689,020; 4,832,604; 4,932,800; 5,056,945; 5,143,463; 5,876,134; 6,019,534; 6,347,898; and 6,439,791. Various designs for these slip over grip accessories are also prevalent, such as U.S. Des. Pat. No. 414,807. (The disclosures of all of the foregoing patents are expressly incorporated herein by reference.)
Problems with slip over grip accessories for writing implements are due to such devices being made of a single, unitary material that must accommodate multiple, often contradictory functions, such as easy sliding placement over the implement, and staying in position and not sliding off once placed.
In light of the foregoing, various objects of this invention are to provide an improved grip accessory that is easier to slide onto an elongate instrument, while maintaining the placement of the accessory after placement.
In one embodiment the inventive grip accessory comprises an inner portion or core comprising a relatively non-elastomeric material surrounded by outer portion or sheath having a relatively elastomeric material, the entire accessory having a bore adapted to accept an elongate instrument. In related embodiments, the core has at least one aperture and the outer portion has at least one ridge that extends through the aperture to engage the outer surface of an elongate instrument inserted into the bore.
In another embodiment this invention provides a method for manufacturing a grip accessory having an outer portion and an inner portion, comprising injection molding said inner portion from a non-elastomeric polymeric composition and overmolding onto said inner portion an outer portion from an elastomeric polymeric composition.